India-born former top federal prosecutor Preet Bharara, who received a phone call from US President Donald Trump just two days before he was fired, said he "was done with" the American leader and did him a favour by not returning his call.

"I was doing everyone a favour by not returning the call.

I was doing the President a favour by not returning the call," Manhattan's former prosecutor said during a conversation last week with New York University's School of Law Dean Trevor Morrison here.

Two days before he was fired, 48-year-old Bharara had got a phone call from Trump's office asking him to call the President back. Bharara did not return the call. Asked if he had considered returning that call, Bharara said there are lots of regulations regarding how contacts should be made between the White House and the Justice Department.

"This is a man who campaigned day after day after day on the argument that (former President) Bill Clinton met with the sitting Attorney General during the pendency of an investigation," Bharara said, referring to the controversial meeting in Phoenix between Clinton and Loretta Lynch.

Trump had repeatedly said during the campaign trail that he did not believe that talks about investigation into Hillary Clinton's use of a private email server had not come up during that meeting between her husband and Lynch and that the two had just talked about their grandchildren and other frivolous things.

Bharara said any interaction between him and Trump could have raised doubts in people's minds over any future investigation his office would have undertaken.

"Who on earth was going to believe that the President of the US in a remarkable and unprecedented fashion is cultivating a relationship with the US Attorney in Manhattan, whose jurisdiction includes various things, only to shoot the breeze Who is going to believe that," Bharara said.

"I saved a lot of people a lot of grief (by not returning the call). At that point I was kind of done with him (Trump) so I didn't return the call," Bharara said.

Referring to him being unceremoniously fired, Bharara recalled the meeting held with much "fanfare" between him and then president-elect Trump in Trump Towers in Manhattan shortly after the presidential elections. He said Trump had then explicitly asked him to stay on for another term.

Bharara also stressed the independence of the US Attorney s Offices.

"The mass of what goes on in any US Attorney's Office is not political and doesn't become political, no matter who the president is," Bharara said.

"My job was not to serve the president, whether that s Barack Obama or Donald Trump or anyone else. It was to serve the public, and to serve the interests of justice," he added.

Very proud of my Indian heritage: Preet Bharara

India-born former top federal prosecutor in Manhattan Preet Bharara said he is very proud of his Indian heritage which made him more compassionate and tolerant towards other people.

Bharara, who was fired by President Donald Trump as US Attorney for the Southern District of New York after he refused to quit, is now a distinguished scholar in residence at New York University s School of Law where he continues working on issues like criminal and social justice, honest government, national security, and corporate accountability.

"I am an American, I happen to be an Indian-American. I am very proud of my background, my roots and my heritage. I am a huge Springsteen fan...but I also listen to Bhangra music, which is a kind of Punjabi music," Bharara said during a conversation last week with New York University's School of Law Dean Trevor Morrison here.

Asked about his heritage and background has shaped his personal and professional life, Bharara said he comes from a multi-cultural background and his children know about their "Indian heritage and also about being American".

Bharara said people would ask him whether his being of Indian heritage and member of a minority group made him more compassionate and tolerant towards other people.

"I say I suppose it does. But what has mattered more to how I think about things is not the fact that I am an Indian- American but that I am an immigrant," he said adding that he and his family are grateful to what America has given them.

He recalled how his father came to the US with nothing but 40 years later his son became the chief federal law enforcement officer in the financial capital of world.

"The first Indian-American US attorney appointed by the first African-American President. That is not a small thing in the minds of some people...So I began to appreciate that," he said.